You can create a designer with Thunder for your widget and in it add a pageSelector (again with thunder). For this purpose you only need a Guid public property in your widget, which will be associated with the PageSelector. We have recorded a demonstrative video for you, showing how I add such selector to a sample widget designer with Thunder. We're also attaching the sample widget and the sample designer.
You could try using the same approach and inform us if you encountered any problem.
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